Electromagnetic relay



Jan. 24, 1950 .1. c. HAMILTON 2,495,325

ELECTROMAGNETIC RELAY Filed Dec. 22, 1944 2 Sheets-Sheet 1 Jan. 24,- 1950 J. c. HAMILTON amc'momamrc RELAY 2` Sheets-Sheet 2 El@ E'.

Filed Dec. 22, 1.944

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JMUFHE UNITED STATES PATENT oFFicE ELECTROMAGNETIC RELAY James C. Hamilton, Lexington, Mass., assigner to Combustion Control Corporation, Cambridge, Mass., a corporation of Massachusetts Application 22, .1944, Serial No. 569,388

This invention relates to electric switching apparatus and more particularly 'to electromagnetic relays.

It is the main object of the present invention to provide an electromagnetic relay which is especially suited for installation in equipment where absolute reliability, ruggedness, and compliance with various safety requirements and regulations are imperative.

Other objects of the invention are to provide a magnet relay having several sets of currentcarrying conductors which are electrically and mechanically completely separated from each other and shielded in such a manner that they cannot be bridged by foreign objects or connected by air gaps that might promote arcing between contact elements of considerably diierent potential; to provide such relay apparatus which is composed of a minimum number of parts requiring a minimum amount of assembly operations, to provide a magnet relay which has completely separated, protected and especially sturdy main lead-in conductors, and similarly arranged switching elements; to provide such a relay which has very easily accessible terminals located conveniently on one side of the apparatus; to provide such a relay which has a practically unbroken contour within which are contained all moving enclosed elements, the assembly offering little opportunity for extraneous parts catching, or foreign particles collecting thereon; and generally to provide an electromagnetic relay of this type which is so organized that it includes the above-mentioned features with lowest possible expenditure of material and assembly work reconcilable with rugged and yet exact and safe construction.

These and other objects, aspects and features of the invention will be more fully apparent from the following description of a practical embodiment illustrating the genus of the invention. The description refers to drawings inwhich Fig. 1 is a side elevation of an electromagnetic relay according to the invention, with open contacts;

Fig. 2 is a side elevation similar to Fig. 1, with the contacts closed;

Fig. 3 is a section on line 3-3 of Fig. 2, portions of which are shown in elevation;

Fig. 4 is a bottom view oi the relay according to Figs. l and 2;

Fig. 5 is a section on line 5-5 of Fig. 3;

Fig. 6 is asection on line I-S of Fig 2;

Fig. 'I is a section on line 1-1 of Fig. 3; and

Fig. 8 is a section on line 8 8 of Fig. '7.

In Figs. l to 7, numeral I indicates a base block made of insulating material. This block has essentially the form of a T, with face 2 that is ilat excepting for the protective projections to be described hereinbelow, and suited for mounting the relay on a flat surface, for example plate 3 6 Claims. (Cl. 200-104) of an apparatus chassis or switchboard. The

transverse portion 5 of block I extends over practically the entire width of the block (Figs 3 and 4) and carries imbedded therein a number of rigid contact bars II, I2, I3, Il and Il (Fig. 3). These contact bars may be arranged in two groups belonging to different portions of a circuit and, if desired of different cross sections corresponding to different current-carrying requirements. By way of example, contacts II and I2, which may have a comparatively high potential, are shown as somewhat heavier than conductors I3, I4 and I5 which may be of low voltage. The contact bars extend at both ends beyond portion .5 of block I. The outer ends of the bars II, I2 constituting one contact group are separated by a barrier I9 from bars I3, I4, I5 constituting a second group. The inner ends of the bars are similarly separated by a barrier 20 in the usual manner provided with contact points of suitable material.

The block I may consist of any suitable insulating material with the contact bars fixed therein in appropriate fashion, but I prefer to imbed these bars into the block while the latter is molded according to the method set forth in my copending application Serial No. 582,914, illed March 15, 1945, now abandoned.

The longitudinal portion of kblock I is provided with openings II8, IIS (Figs. 4, 6) for wires leading to the magnet coil 40 (Figs. 1, 2, 6). It the mounting element 3 consists of insulating material, such openings will often be satisfactory. In other instances however, for example if plate 3 is made of metal, it may be preferable to provide bosses 2l, 22 containing, preferably moulded thereinto, magnet coil leads 23, 24, which extend on both sides beyond the bosses and have the purpose of carrying current to the magnet coil of the relay. These bossesy may be integral with block I or, as indicated in Fig. 6 they may be formed separately with threads for screwing ihem into corresponding threads of openings I IB,

The base block I has acorner portion 26 which locates one leg of the core structure 3| which is provided with three legs 32, 33, 34. Leg 32 has punched thereinto two openings 23, 29 corresponding to openings I8, I9 which may be provided with bosses 2l and 22, as indicated in Figs. 4 and 6. Leg 32 also serves for fastening the magnet core structure to block I, by means of screws 35 and 36 (Fig. 4) which may be staggered with respect to openings H3, H9. A mounting screw 38 is firmly inserted into a tapped hole 39 of core leg 32 and has an extension projecting in the direction of bars II to I5, for the purpose oi' receiving a nut (not shown) by means of which the relay can be rmiy fastened to the mounting element 3.

The magnetic core leg 33 carries in conventional manner a magnet coil 40, the ends oi which may lead through openings H0, Il! or are connected, as by soldering, to the ends 4|, 42 of magnet coil leads 23, 24 as shown in Fig. 1.

The third leg 34 is provided with two brackets 5|, 52 which extend inwardly and have holes 54,

55, which are adapted to receiveI a hinge pin 50 fastened thereto in the manner to be described below.

The magnetic circuit is completed by armature iron which is secured. by means of two screws 13, 14 (Figs. 1, 8) to an armature block 00 now to be described.

The armature block consists of two portions both of insulating material, namely a carrier plate 0| and a cover plate 02 (Figs. 1, 5, 7, 8). The cover plate 82 is provided with two bosses 03, 04 (Figs. 3, 7) which fit into somewhat larger, corresponding recesses 35, 00 (Fig. 8) of carrier plate 0|. These recesses are at their openings surrounded by somewhat wider, at and shallow recesses 81, 08 (Figs. 3, 7) which are open on the side toward the contact bars to I5 and correspond to widened portions at the base of bosses 83, 84 of cover plate 02. Carrier plate as well as cover plate have two holes through the center of bosses 03, 84 and through plate 0| below the recesses 85, 80, respectively, for screws 13, 14 mentioned above, which screws join`the two portions of the armature block to each other and to armature iron 10. Cover plate 02 has appropriate recesses for the sunk heads of screws 13 and 14.

The cover plate 02 is provided with a dividing barrier |00 (Figs. 1, 3, 5, 8) which is integral therewith and which ilts into a groove |0| of carrier plate 8|'. This dividing barrier extends into the space between the fixed contact bar groups mounted on block andprovides with the abovementioned barrier of block (Figs. 1, 3, 7) two securely separated chambers for the two sets of contacts. It will be evident that barrier |00 is not necessarily integral with cover plate 02 but may be integral with carrier plate 0| and nt into a groove of plate 02; the barrier |00 may also be formed as a separate piece suitably iitted and secured to plates 0| and 02.

The armature block contains two sets of contact springs 92, $3 (Figs. 3, 7, 8) ,with bridge portions 95, 96 that t into recesses 01, 00, and have holes that fit around bosses 03, 04. It will be evident that, with screws 13, 14 properly tightened, the contact springs 02, 03 are firmly iixed to the armature block, these screws at the same time rmly joining the two portions of the armature block to the armature iron 10.

The contact springs 02, 93 have contact prongs ||2, H3, H4, H5, which extend beyond the ends of bars to I5 and are, similar to the latter, provided with appropriate contact points.

The carrier block 8| is further provided with a lifting ridge |20 upon which contact springs to |5 rest when the armature block 00 is tilted away from the magnet, whereas the springs leave the lifting ridge upon making contact with the contact bars to I5. It will be evident that, due to the resiliency of contact springs to III, these springs will, with the armature block lifted, rest firmly against the ridge |20, which thus keeps them in proper alignment and assures simultaneous contacting at all points. Contact springs 02 and 93 may of course have any number of prongs, depending upon the desired number of contact points.

As mentioned above, the separating barrier |00 of cover plaie l2 extends beyond the ends o! contact prongs to Ill and overlaps with barrier 20 of base block In this manner the two groups of contacts. namely I2 and H2, and i3 to Il and ||3 to Hl, are eiiectively separated from each other, for mechanical as well as electrical purposes. It will be evident that more than two contact groups can be eiiectiveiy separated in this manner, if desired.

The outer edge |23 (Figs. 1, 5, '1) of cover plate 02 corresponds to an angular recess |20 oi base plate I. This provides for an eiiective closure between base block and block l0 especially when the contacts are closed, but even in "open" position of the armature as shown in Fis. 1. The outer end |35 of carrier plate 0| and armature iron 10 extends beyond transverse portion 0 of base block I and constitutes an insulating barrier between the armature metal and the contacts, and it also provides a stop for the armature.

The armature iron 10 has two lugs |04, Ill corresponding to brackets 04, l! of the core, as above described. The hinge pin 00 (Figs. 5. 6) may be inserted into a groove |08 of plate 10, in order properly to locate the pivot point with respect to the plane of contact of plate 10 and magnet core 33. The hinge pin fits loosely in` lugs |54, |05 but is fixed in brackets 04. 0l by expanding it within holes 04, Il, as indicated by the peen marks shown in Fig. 6.

The armature iron 10 is also provided with one semicircular and one circular cut-out, clearly indicated in Eig. 6, and adapted to receive one fastening hook 51 of spring 00, whose other end is hooked to a screw eye 0|, fastened to the core 3|. The armature iron 10 also has two tapped holes 1|, 12 adapted to receive bolts 13, 14 as above described.

It will be evident that the lateral openings of the armature block 00 may be provided with closing walls similar to center barrier |00. In cases where it is justified to retain the contacts fully enclosed, these outer walls provide complete protection of the switching elements.

Instead of using the tension spring herein shown a compression spring of metal or rubber may be used,v in which case the pivot will be suitably placed in conformity with the action of the spring.

This relay operates as follows.

Coil conductors 23 and 24 having been connected to an energizing relay circuit, and the terminals of contact bars to I0 to the apPrOplitc circuit elements of apparatus to be controlled by the relay, the contact points of to Il. and to ||5 will remain separated so long as the magnet is deenergized. Upon energization oi' coil 40. armature iron 10 is attracted by magnet core 33. and the spring contacts I and I'Il, having been lifted from ridge |20, conductively connect conductor wires and |2, and I3 to l5, respectively, making circuit between the wires connected to the contact bars.

When the current supply to the coil 40 is interrupted. spring 50 lifts the armature block, ridge |20 disconnects the contact springs to ||I from the corresponding rigid contact bars to l5 until the end portion |35 of plate 0| contacts block portion l, and the respective circuits are interrupted.

It will be noted that the contact points are protected against disturbing frontal interference in open as well as in closed position, as shown in Figs. 1 and 2, respectively. It will further be noted that the present construction permits separation of all lead wires from the relay proper, on

the other side of the mounting plate 3, and easyy accessibility of the lead connections.

It should be understood that the present disclosure is for the purpose of illustration only and that this invention includes all modifications and equivalents which fall within the scope of the appended claims.

I claim:

1. In an electromagnetic relay of the type having a magnetic core structure associated with an energizing coil, and an armature structure including a magnetic armature member movably secured to the core structure, the combination of a solid insulating base block fastened to said core structure, land to which are rigidly fastened two sets of substantially stationary and rigid contact bars freely extending beyond a face of said block, and carrying on said face a barrier extending toward the ends of, and separating said contact sets; an insulating base plate secured to said armature member, and carrying two sets of contact springs constructed and arranged with freely extending ends to bridge at least two of said contact bars; and a cover plate secured to said base plate, one of said plates having a groove between said contact springs and the other plate having a barrier which extends into said groove and also projects between said contact springs and said contact bar sets so as to overlap said base block barrier.

6 means; and the other plate having a barrier extending into said groove and between said contact means and said contact bar sets, said base vplate and said cover plate extending over said contact means and said sets, thereby separating said two sets and their corresponding contact means.

4. A combination according to claim 3 wherein either of said resilient contact means comprises a plurality of leaf springs joined together at one end.

5. `In an electromagnetic relay of the type having a magnetic core structure, with which an energizing coil is associated, and to which a magnetic armature is movably secured, the combination of an insulating T-shaped base block, the longitudinal portion of which is fastened to said core structure and the transverse portion of which has integrally molded therein substantially stationary and rigid contact bars both ends of which extend from said transverse portion, said longitudinal portion containing conductors adapted to leadv to said coil and extending transversely through said core structure; an armature block including a base plate secured on one side to said magnetic armature member, a cover plate secured to the other side of said base plate, and two resilient contact means free from external electrical 2. In an electromagnetic relay of the type havbination of an insulating base block which is fastened to said core structure and which contains rigidly fastened thereto two sets of substantially stationary and rigid contact bars, with an armature block including an insulating base plate secured on one side to said magnetic armature member, a cover plate secured to the other side of said base plate, and two resilient contact means free from external electrical connections and each arranged to bridge at least two of said contact bars and secured between said base plate and said cover plate, one of said plates having a groove between said resilient contact means and the other plate having a barrier extending into said groove and between said contact means and said contact bar sets, and said base plate and said cover plate extending over said contact means and said sets, thereby separating said two sets and their corresponding contact means.

3. In an electromagnetic relay of the type having a magnetic core structure, with which an energizing coil is associated, and to which a. magnetic armature is movably secured, the combination of an insulating T-shaped base block, the

' longitudinal portion of which is fastened to said core structure and the transverse portion of which has fixed thereto substantially rigid contact bars, with an armature block including an insulating base plate secured on one side to said magnetic' amature member, a cover plate secured to the other side of said base plate, and two resilient contact means free from external electrical connections and each arranged to bridge at least two of said contact bars and secured between said base plate and said core plate; one o1 said plates having a groove between said resilient contact connections and each arranged to bridge at least two of said contact bars and secured between said base plate and said cover plate, one of said plates having a groove between said resilient contact means and the other plate having a barrier extending into said groove and between said contact means and said contact bar sets, said base plate and said cover plate extending. over said contact means and said sets, thereby separating said two sets and their corresponding contact means.

6. In an electromagnetic relay of the type having a magnetic core structure, with which an energizing coil is associated, and to which a magnetic armature is movably secured, the combination of an insulating T-shaped base block, the longitudinal portion of which is fastened to said core structure and the transverse portion of which has fixed thereto substantially rigid contact bars, and carries a projecting barrier between said bars, with an armature block including an insulating base plate secured on one side to said magnetic armature member, a cover plate secured to the other side of said base plate. and two resilient contact means each arranged to bridge at least two of said contact bars and secured between said base plate and said core plate; one of said plates having a groove between said resilient contact means; and the other plate having a barrier extending into said groove and between said contact means and said contact bar sets, and over- .l

lapping the barrier on said base block.

JAMES C. HAMILTON.

REFERENCES CITED The following references are of record in the file of this patent:

2,284,644 Dubilier Jixne 2. 1942 

